Do you think iPhones don't have 5G on T-Mobile? They certainly do.
Also it's always been that way. My first iPhone was a 5. I paid 200.00 for it as part of the plan when I switched to then Sprint. I didn't pay anything for the 6 or 7, because the trades literally paid the entire cost of the new phone. Then I didn't trade the 7, because they wanted to charge me for it. I added a line for the XR, and traded one of my wife and I's 7's for and got for free. I added another line for this most recent one, and traded another 7 and this time I think I pay 7 dollars a month for it. But basically I've paid 200.00 plus 7 bucks/mo for all of the phones I've owned since something like 2013.
The laptops are completely overpriced. But owning the one of the phones can be incredibly inexpensive if you play your cards right.